This invention relates to a vehicle traction control system and method.
Various traction control methods have been proposed for preventing an excessive slip condition of the driven wheels of a vehicle during vehicle acceleration by minimizing/optimizing the slip of the driven wheels. Such traction control systems can be classified into full feature systems with brake and engine torque management, engine torque only control systems, brake torque control only systems, and transmission gear ratio control.
Full feature traction control systems make use of a dedicated control module which modulates brakes and executes some form of engine torque management using spark, fuel or throttle control. These systems have excellent controllability but suffer from complexity and high hardware cost.
Engine torque management systems typically use fuel cutoff or throttle control as the primary control mechanism, with some spark trims to achieve torque reduction. While fuel control can be relatively smooth in a V6 or V8 engine with individual cylinder cutting, this method is particularly coarse if used on a throttle body injection or a simultaneous multi-point fuel injection system.
Brake control can be very quick acting, but searching the surface for traction with brake control often does not provide for smooth control. Furthermore, brake only systems usually require additional hardware which provides the capability of applying the brakes upon demand.
The challenge remains to devise a low cost, simple, and smooth traction control system utilizing existing control methods which are available in a highly integrated vehicle control system.